https://github.com/tkellen/node-liftoff/blob/a5f0f1b0dce78bc37a5ad1ae0ea374437bb4efe8/index.js#L81

Since the modulePath is empty thus it thinks it is not installed, however since the module is installed globally the reported path is valid.

As a side note why is this even here, since how can you even invoke the CLI command without even having knex installed?

Perhaps the root of the problem is due to node-liftoff not resolving symlinks, meh just a thought